Power transmission mechanism



Feb. 12, 1952 M. w. GREDELL. 2,585,114

POWER TRANSMISSION MECHANISM Filed April '7, 1948 INVENTOR. MARCELLUS m REDELL mm W A TTORNEV Patented 12, 1952 UNITED POWER TRANSMISSION MECHANISM Marcellus W. Gredell, Detroit, Mich.

Application April 7, 1948, Serial No. 19,505

7 Claims.

This invention relates to power. transmissions, and has particular reference to devices such as disclosed in my co-pending application {5. N. 767,810 filed August 9., 1947, and which was abandoned, of which this application may be considered a continuation in part.

An object of the invention is to generally improve devices of the character indicated, and to provide a stop, reverse and forward drive mechanism, which is simple in, construction, economical to manufacture, and efficient in operation.

Another object of the invention is to provide .a power transmission unit which may readily be secured to a gasoline engine crank case, whereby the drive shaft of the engine becomes the drive shaft of the transmission and the en ine thrus and main bearings serve as corresponding bearings for certain of the driving components of the transmission. 7 V 7 Other objects and advantages of the invention and the description of elements c.om mn to "both applications are set forth "in more .comple e'detail in my co-pendingapplioation to which refer- .ence is made for. greater certainty.

In the accompanying drawing Fig. 1 is an elevational view, with parts broken away and parts in section, of a device embodying the invention.

Fig. 2 is a fragmentary detail, partly :in section, and with parts broken away, showing the shifting mechanism. I a

Fig. ;3 is a sectional view taken substantially on the line 33of Fig. 2. y 7

Referring now more particularly to the drawings, it will be understood that in the embodiment herein disclosed, the reference character 1 indicates 'a housing having an end cover plate}! and a lighter top closure plate 9, whicharerespectively secured to the housing "I, by machine screws I0 and II. The moving parts hereinafter described are all intended to run in a bath of oil, therefore, I provide an oilproof gasket i=2 between the housing I and cover plate 8, and ,an oil seal assembly I3 about the driven shaft ,M to prevent the leakage of oil from thehousing I.

The housing I is provided with lu s (notshowrr) whereby it may be boltedto the crankcase o f -a conventional small gasoline engine, such manufactured by Briggs & Stratton, or the-Clinton Manufacturing Co.

The housing I is provided at the input side with an opening I5, which is substantially larger than the outside diameter of the drive shaft I6 of the engine to which the transmission is .to ,be mounted, so that the enginedrive shaft I6 may extend well into the transmission housing and .jing elements as hereinafter described.

serve as the driving shaft for the transmission assembly and so that the main. bearings and thrust bearings of the engine will serve in the same capacity for the driving components of the transmission assembly.

The side I! of the casting is provided on its inside with an internal boss I8 which is machined out. -as at I9. to accommodate a ball hearing assembly 20 in which is positioned one end of a sleeve 2i, which sleeve 2I extends to the opposite side of the casting and into the opening I5. A pilot shaft 22 is positioned in one end of the sleeve 2], and the engine drive shaft I6 is adapted to extend well into the sleeve ;2l and contact the end of the pilot shaft 22. Keyed to the sleeve 2| and to the drive shaft I6, as at 23, and adapted to rotate therewith is a, sprocket wheel 24. A set screw 25 extends through a borein the collar 26 of the sprocket wheel, and is adapted to contact the key 23 to hold itin position, and further serves to prevent the axial movement of the sprocket wheel 24.

A gear 21 is also keyed to the sleeve 2i and to the pilot shaft 22, and is in turn held against axial movement on the sleeve by means of a set screw 28. The driven shaft I4 is supported in tapered roller bearing assemblies '28 and 29 which are respectively mounted in recesses formed in the side wall 3 0 of the casting and the cover plate 8. The taper of the bearing assemblies 28 and 29 serves to absorb th thrust of the driven shaft I4 when the device is in operation, .as more particularly described in my co-pending application.

The driven shaft I4 is formed-with a shoulder 3| which engages the inner race 32 of the roller assembly 28, and is adapted to impart the backward thrust of the shaft M to the hearing assembly .28. The forward thrust is imparted to the bearing assembly 29 through .the shoulder 33, and the elements hereinafter described.

Mounted for rotation on a bushing 34 carried by the driven shaft 14 is a sprocket wheel 35 which is formed with a hub portion 36, and an undercut collar portions] which serveas clutch- The sprocket wheel 2d and the sprocket wheel 35 areconnected by means of a chain 38, and a1 .ways rotate in the direction indicated by the arrows.

Mounted for rotation on the bushing 39 positioned on ,thedriven shaft 1 4 is agear so, the teeth of ,which meshwithltheteethof the gear 21, and rotatesin ,the direction opposite to the direction .of rotationofthegear 27. The gearllflhas a hub portion 4|, and an undercut portion 42 which ball bearings 50. Clutch springs 5I and 52 are loosely mounted about the enlarged area 43 of the shaft I4 and the portions 36 and M respectively of the sprocket and the gear 40.

freely rotatable on bushings mounted on said driven shaft said last named sprocket wheel and said gear having clutching elements thereon, a clutch collar concentrically mounted on the enlarged section of said driven shaft, means to shift said clutch collar on said driven shaft, and spring means adapted to contact said clutch collar said enlarged section of said driven shaft and said clutching elements formed on said last The clutch collar is adapted to be shifted axially on the enlarged portion 43 of 'the shaft I4 by means of rollers 53A and 53B pivoted to a yoke 53 which is rockable on the shaft 54, thelatter being rocked by means of a lever 54A, as is more fully described in my co-pending application to which reference is hereto made for greater certainty.

Locking rings 55 and 56 are adapted to engage suitable grooves formed in the driven shaft I4, and serve to hold the washers 51 and 58 in position. 1

In operation the device functions as follows:

The sprocket 24 and the gear 21 rotate in the direction indicated by the arrows under the influence of the engine crank shaft IS. The sprocket 35, which is driven by the chain 38 also rotates in the same direction. The gear 43, however, rotates in the reverse direction. Therefore, when the clutch collar 45 is shifted to the left from the position as shown in Fig. l, the angular face 46 of the clutch collar engages a corresponding face formed on the clutch spring 5I creating a frictional engagement. At the same time the spring 5I is moved to the left so that the opposite end of the spring contacts the undercut face formed on the member 31 of the sprocket 35. After pressure is maintained against the spring 5| it starts to tighten on the clutching element 35 of the sprocket 35, and the enlarged portion 43 of the shaft I4, whereby the direct drive is accomplished.

When the clutch collar 45 is moved to the right from the position as shown in Fig. 1, the clutch spring 52 is forced into engagement with the members M, 42, and 41, and the enlarged portion 43 of the shaft I4, whereupon the reverse rotation of the gear 40 is imparted to the drive shaft I4, whereby the reverse drive is obtained.

When the clutch collar 45 is in the postion as shown in Fig. 1, the sprockets 24 and 35 and the gears 21 and 40 rotate freely on their respective shafts and the device is in neutral position.

Having described my invention, what I claim and desire to secure by Letters Patent is:

1. A power transmission device comprising the combination of a housing having front and rear walls, an opening in the front wall adapted for the insertion therethrough of an engine crank shaft, a rotatable sleeve mounted at one end in the rear wall of said housing and arranged to engage said crank shaft and rotate therewith, a sprocket and a gear mounted for rotation with said sleeve, a driven shaft having an enlarged section mounted for rotation in said housing and having one end extending beyond the rear wall of said housing, a sprocket wheel and a gear named, sprocket wheel and gear.

2. A power transmission comprising in combination a housing adapted to be secured to the housing of a conventional power generator, a sleeve mounted for rotation in said first named housing, said sleeve being arranged to engage the drive shaft of said power generator, a sprocket wheel and a gear mounted for rotation with said sleeve, a driven shaft, having an enlarged central area, rotatably mounted in said first named housing, a sprocket wheel freely mounted on a bushing on said driven shaft it being connected by a chain to said first named sprocket wheel, a gear freely mounted for rotation on a bushing on said driven shaft and having its teeth meshed with the teeth of said first named gear said freely mounted sprocket and gear having extensions formed thereon, a clutch collar slidably keyed to the enlarged portion of said driven shaft, and spring members freely mounted concentrically on the enlarged portion of said driven shaft and said extensions formed on said last named sprocket and said last named gear, and means for shifting said clutch collar against said spring members.

3. A power transmission device comprising a housing adapted to be secured to the housing of a conventional power generator, an opening in the wall of said first named housing adapted to accommodate the drive shaft of said power generator, a sleeve in alignment with said opening and supported at one end for rotation in said first named housing, a sprocket wheel and a gear rotatably mounted on said sleeve, a driven shaft mounted for rotation in said first named housing, a sprocket wheel freely mounted for rotation on a bushing on said driven shaft, a chain connecting said sprockets, a gear freely mounted for rotation on a bushing on said driven shaft and in constant mesh with said first named gear,

said last named sprocket and said last named gear having clutch means formed thereon, an enlarged area formed on said driven shaft, a clutch collar slidably keyed to said enlarged portion and having clutching elements formed thereon, and spring members concentrically mounted on opposite sides of said clutch collar and about the enlarged portion of said driven shaft and arranged to contact the clutch means formed on said sprocket and said gear.

4. A power transmission device comprising in combination a housing, means for securing said housing to a power generator having a drive shaft, an opening in one wall of said housing adapted to accommodate the drive shaft of said power generator, a rotatable sleeve in said housing keyed to said drive shaft, 2. sprocket wheel and a gear keyed to said sleeve, a driven shaft mounted for rotation in said housing and having an enlarged portion centrally positioned in said housing, a sprocket wheel freely mounted on a bushing on said driven shaft at one side of said enlarged area and adapted to be driven by said first named sprocket wheel, clutch means formed on said sprocket wheel including a collar having a diameter substantially the same as the diameter of the enlarged portion of said driven shaft, a gear mounted for rotation on a bushing on said driven shaft at the opposite side of said enlarged portion and having a collar of the diameter substantially the same as the diameter of said enlarged portion of said driven shaft, a clutch collar slidably keyed to the enlarged portion of said driven shaft, means for shifting said clutch collar, and spring means positioned on opposite sides of said clutch collar and adapted to contact the said clutch collar and the large portion of said driven shaft and the respective collars of said last named sprocket and said last named gear.

5. The combination defined in claim 2, including rollers positioned at opposite sides of said clutch collar, said rollers being pivoted to a yoke, the latter being rockable by a lever positioned on the exterior of said housing.

6. The combination defined in claim 4, in which said clutch collar is undercut at either side to provide clutch faces arranged to be contacted by said spring means, and said clutch collar is also provided with a pair of concentric rotatable rings having ball bearings therebetween.

7. The combination defined in claim 4, in which the sprocket and the gear mounted for rotation on said driven shaft are provided with undercut faces arranged to be contacted by the said spring means.

MARCELLUS W. GREDELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,101,515 Schmitter Dec. 7, 1937 2,235,266 Starkey Mar. 18, 1941 2,314,549 Milbrath Mar. 23, 1943 FOREIGN PATENTS Number Country Date 740,132 France Jan. 21, 1933 

